The "after construction" mounting of hangers for ceiling fans, heavy lighting fixtures, potted plants, chairs, etc., has heretofore posed a serious problem in inaccessible locations. Standard electrical trade installation methods for ceiling electrical boxes in new construction will safely hold approximately a 10-pound static load. Ceiling fans, for example, present from 25-pound to 100-pound dynamic loads. Therefore, modifications must be made to safely hang heavier dynamic loads.
Adding ceiling fans or other heavy hanging fixtures to the standard electrical installation in a two-story structure between floors is especially difficult. Additional complexity is introduced when the installation is to be effected on inclined surfaces, such as cathedral or vaulted ceilings. There are two options to effecting such an installation. The first involves the removal or modification of the ceiling covering to provide access. The second, and generally preferred method, involves accomplishing the entire installation through a standard 4-inch electrical box hole in the ceiling. These holes may be located at various distances between ceiling joints.
The conventional method for installing a heavy-duty hanger is to add a structural piece between the ceiling joists from which the electrical box and ceiling fan or other device is hung. If the installation is between a ceiling and an attic, or if there is no top ceiling cover or if the ceiling cover is off, simple and various reliable installation methods are available. However, if the installation must be accomplished through the 4-inch electrical box hole, the hanger must be inserted through the hole and manipulated to form a structural member between the ceiling joists. Furthermore, these methods must consider and take into account the angular forces (torque) exerted upon the hanger assembly by the fixture to retain attachment integrity. Such angular forces result from gravity acting upon the hanging fixture. This gravitational force is translated to and acts upon the hanger assembly via an attachment assembly which attaches the fixture to the hanger assembly. Thus, the attachment assembly acts as a lever upon which the gravitational force acts, thereby exerting a torque on the hanger assembly which attempts to rotate the hanger assembly about its long axis.
In the prior art, some devices have been proposed for providing interjoist supports which can be installed through a small ceiling opening, and exemplary of such state of the art devices are depicted and described in the following U.S. Patents, namely: Steketee--U.S. Pat. No. 2,140,861; Codgill--U.S. Pat. No. 3,518,421; Lenon--U.S. Pat. No. 4,405,111; Reiker--U.S. Pat. No. 4,463,923; and Propp et al.--U.S. Pat. No. 4,659,051. However, the prior art does not address the problem relating to the angular forces or torque exerted upon the hanger assembly installed in an inclined or sloped ceiling which affects the attachment integrity thereof.
These and other limitations and disadvantages of the prior art, and especially of the aforementioned patents, are overcome with the present invention and commercially acceptable embodiments of a hanger adapter the like, together with an installation aid, are herein provided. Such embodiments are especially suitable for use by a person of only limited skill to easily install the hanger adapter of the present invention along with the respective hanger assembly through a small ceiling opening in an inclined or sloped ceiling. The embodiments of the present invention are also capable of use for installations in difficultly accessable locations which are beyond the capabilities of the prior art.